On Steam and Brines 155 



The least soluble of these salts is chloride of barium, 

 requiring 64 grms. of condensed steam for solution, and the 

 most soluble is sulphate of ammonium, which requires only 

 25 grms. 



Apparatus and Method of Experimenting. The apparatus, 

 Fig. i, consists of the lamp, A, the steam generator or boiler, 

 B, the U-tube or receiver, D, and the connecting tube, G. In 

 the laboratory a gas lamp was used, except when it was 

 wished to check the results of the fuel consumed, when a 

 spirit lamp was used, and it was weighed before and after 

 the experiment In the experiments at high levels, where 

 gas was not available, spirit was used. The lamp employed 

 was one of a French pattern, and forming a part of the 

 Rfahaud a double flamme forcee of smallest size, which has 

 a large sale for domestic purposes. It is the most efficient 

 pattern of spirit lamp with which I am acquainted, and as it 

 is especially constructed for use in travelling, it was very suitable 

 for my high-level work. It holds about 250 c.c. of spirit. 



The steam generator or boiler, B, used at high levels, was 

 a flask made of spun copper and of 500 c.c. capacity. A 

 suitable charge is 300 c.c. of water. With such a charge, and 

 heated by the French lamp, the water boiled in six minutes, 

 with a consumption of 12 grammes of spirit. While keeping 

 steam at the rate suitable for the experiment, the lamp con- 

 sumed 21 grammes of spirit in fifteen minutes, and evaporated 

 92 grammes of water. For experiments in the laboratory I 

 use a large copper flask of 2 litres capacity. This is a very 

 convenient laboratory vessel. They are manufactured to 

 replace the glass flasks of Napier's coffee machines for use in 

 restaurants, and they can be had in larger sizes. A copper 

 flask can always be obtained at short notice from a plumber, 

 by getting him to fit a neck to one of the copper balls which 

 are used as controlling floats for cistern taps. These are to 

 be had of all sizes up to 10 inches diameter, and are very cheap. 



The receiver, D, has the appearance and shape shown in 

 the Fig. The actual dimensions are variable, according to 

 the quantity of salt on which it is proposed to operate, and 

 according to the length of the thermometer. The working 



